/*
* Vulkan Example - Omni directional shadows using a dynamic cube map
*
* Copyright (C) 2016-2025 by Sascha Willems - www.saschawillems.de
*
* This code is licensed under the MIT license (MIT) (http://opensource.org/licenses/MIT)
*/

#include "vulkanexamplebase.h"
#include "VulkanglTFModel.h"

class VulkanExample : public VulkanExampleBase
{
public:
	bool displayCubeMap{ false };

	// Defines the depth range used for the shadow maps
	// This should be kept as small as possible for precision
	float zNear{ 0.1f };
	float zFar{ 1024.0f };

	struct {
		vkglTF::Model scene;
		vkglTF::Model debugcube;
	} models;

	glm::vec4 lightPos = glm::vec4(0.0f, -2.5f, 0.0f, 1.0);

	struct UniformData {
		glm::mat4 projection;
		glm::mat4 view;
		glm::mat4 model;
		glm::vec4 lightPos;
	};
	UniformData uniformDataScene, uniformDataOffscreen;

	struct UniformBuffers {
		vks::Buffer scene;
		vks::Buffer offscreen;
	};
	std::array<UniformBuffers, maxConcurrentFrames> uniformBuffers;

	struct {
		VkPipeline scene{ VK_NULL_HANDLE };
		VkPipeline offscreen{ VK_NULL_HANDLE };
		VkPipeline cubemapDisplay{ VK_NULL_HANDLE };
	} pipelines;

	struct {
		VkPipelineLayout scene{ VK_NULL_HANDLE };
		VkPipelineLayout offscreen{ VK_NULL_HANDLE };
	} pipelineLayouts;

	struct DescriptorSets {
		VkDescriptorSet scene{ VK_NULL_HANDLE };
		VkDescriptorSet offscreen{ VK_NULL_HANDLE };
	};
	std::array<DescriptorSets, maxConcurrentFrames> descriptorSets;

	VkDescriptorSetLayout descriptorSetLayout{ VK_NULL_HANDLE };

	vks::Texture shadowCubeMap;
	std::array<VkImageView, 6> shadowCubeMapFaceImageViews{};

	// Framebuffer for offscreen rendering
	struct FrameBufferAttachment {
		VkImage image;
		VkDeviceMemory mem;
		VkImageView view;
	};
	struct OffscreenPass {
		int32_t width, height;
		std::array<VkFramebuffer, 6> frameBuffers;
		FrameBufferAttachment depth;
		VkRenderPass renderPass;
		VkSampler sampler;
		VkDescriptorImageInfo descriptor;
	} offscreenPass;

	// Size of the shadow map texture (per face)
	const uint32_t offscreenImageSize{ 1024 };
	// We use a 32 bit float format for max. precision. Depending on the use case, lower precision may be fine and can save bandwidth
	const VkFormat offscreenImageFormat{ VK_FORMAT_R32_SFLOAT };
	// The depth format is selected at runtime
	VkFormat offscreenDepthFormat{ VK_FORMAT_UNDEFINED };

	VulkanExample() : VulkanExampleBase()
	{
		title = "Point light shadows (cubemap)";
		camera.type = Camera::CameraType::lookat;
		camera.setPerspective(45.0f, (float)width / (float)height, zNear, zFar);
		camera.setRotation(glm::vec3(-20.5f, -673.0f, 0.0f));
		camera.setPosition(glm::vec3(0.0f, 0.5f, -15.0f));
		timerSpeed *= 0.5f;
	}

	~VulkanExample()
	{
		if (device) {
			// Cube map
			for (uint32_t i = 0; i < 6; i++) {
				vkDestroyImageView(device, shadowCubeMapFaceImageViews[i], nullptr);
			}
			vkDestroyImageView(device, shadowCubeMap.view, nullptr);
			vkDestroyImage(device, shadowCubeMap.image, nullptr);
			vkDestroySampler(device, shadowCubeMap.sampler, nullptr);
			vkFreeMemory(device, shadowCubeMap.deviceMemory, nullptr);
			vkDestroyImageView(device, offscreenPass.depth.view, nullptr);
			vkDestroyImage(device, offscreenPass.depth.image, nullptr);
			vkFreeMemory(device, offscreenPass.depth.mem, nullptr);
			for (uint32_t i = 0; i < 6; i++)
			{
				vkDestroyFramebuffer(device, offscreenPass.frameBuffers[i], nullptr);
			}
			vkDestroyRenderPass(device, offscreenPass.renderPass, nullptr);
			vkDestroyPipeline(device, pipelines.scene, nullptr);
			vkDestroyPipeline(device, pipelines.offscreen, nullptr);
			vkDestroyPipeline(device, pipelines.cubemapDisplay, nullptr);
			vkDestroyPipelineLayout(device, pipelineLayouts.scene, nullptr);
			vkDestroyPipelineLayout(device, pipelineLayouts.offscreen, nullptr);
			vkDestroyDescriptorSetLayout(device, descriptorSetLayout, nullptr);
			for (auto& buffer : uniformBuffers) {
				buffer.offscreen.destroy();
				buffer.scene.destroy();
			}
		}
	}

	void prepareCubeMap()
	{
		shadowCubeMap.width = offscreenImageSize;
		shadowCubeMap.height = offscreenImageSize;

		// Cube map image description
		VkImageCreateInfo imageCreateInfo = vks::initializers::imageCreateInfo();
		imageCreateInfo.imageType = VK_IMAGE_TYPE_2D;
		imageCreateInfo.format = offscreenImageFormat;
		imageCreateInfo.extent = { shadowCubeMap.width, shadowCubeMap.height, 1 };
		imageCreateInfo.mipLevels = 1;
		imageCreateInfo.arrayLayers = 6;
		imageCreateInfo.samples = VK_SAMPLE_COUNT_1_BIT;
		imageCreateInfo.tiling = VK_IMAGE_TILING_OPTIMAL;
		imageCreateInfo.usage = VK_IMAGE_USAGE_COLOR_ATTACHMENT_BIT | VK_IMAGE_USAGE_SAMPLED_BIT;
		imageCreateInfo.sharingMode = VK_SHARING_MODE_EXCLUSIVE;
		imageCreateInfo.initialLayout = VK_IMAGE_LAYOUT_UNDEFINED;
		imageCreateInfo.flags = VK_IMAGE_CREATE_CUBE_COMPATIBLE_BIT;

		VkMemoryAllocateInfo memAllocInfo = vks::initializers::memoryAllocateInfo();
		VkMemoryRequirements memReqs;

		VkCommandBuffer layoutCmd = vulkanDevice->createCommandBuffer(VK_COMMAND_BUFFER_LEVEL_PRIMARY, true);

		// Create cube map image
		VK_CHECK_RESULT(vkCreateImage(device, &imageCreateInfo, nullptr, &shadowCubeMap.image));

		vkGetImageMemoryRequirements(device, shadowCubeMap.image, &memReqs);

		memAllocInfo.allocationSize = memReqs.size;
		memAllocInfo.memoryTypeIndex = vulkanDevice->getMemoryType(memReqs.memoryTypeBits, VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT);
		VK_CHECK_RESULT(vkAllocateMemory(device, &memAllocInfo, nullptr, &shadowCubeMap.deviceMemory));
		VK_CHECK_RESULT(vkBindImageMemory(device, shadowCubeMap.image, shadowCubeMap.deviceMemory, 0));

		// Image barrier for optimal image (target)
		VkImageSubresourceRange subresourceRange = {};
		subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
		subresourceRange.baseMipLevel = 0;
		subresourceRange.levelCount = 1;
		subresourceRange.layerCount = 6;
		vks::tools::setImageLayout(
			layoutCmd,
			shadowCubeMap.image,
			VK_IMAGE_LAYOUT_UNDEFINED,
			VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL,
			subresourceRange);

		vulkanDevice->flushCommandBuffer(layoutCmd, queue, true);

		// Create sampler
		VkSamplerCreateInfo sampler = vks::initializers::samplerCreateInfo();
		sampler.magFilter = VK_FILTER_LINEAR;
		sampler.minFilter = VK_FILTER_LINEAR;
		sampler.mipmapMode = VK_SAMPLER_MIPMAP_MODE_LINEAR;
		sampler.addressModeU = VK_SAMPLER_ADDRESS_MODE_CLAMP_TO_BORDER;
		sampler.addressModeV = sampler.addressModeU;
		sampler.addressModeW = sampler.addressModeU;
		sampler.mipLodBias = 0.0f;
		sampler.maxAnisotropy = 1.0f;
		sampler.compareOp = VK_COMPARE_OP_NEVER;
		sampler.minLod = 0.0f;
		sampler.maxLod = 1.0f;
		sampler.borderColor = VK_BORDER_COLOR_FLOAT_OPAQUE_WHITE;
		VK_CHECK_RESULT(vkCreateSampler(device, &sampler, nullptr, &shadowCubeMap.sampler));

		// Create image view
		VkImageViewCreateInfo view = vks::initializers::imageViewCreateInfo();
		view.image = VK_NULL_HANDLE;
		view.viewType = VK_IMAGE_VIEW_TYPE_CUBE;
		view.format = offscreenImageFormat;
		view.components = { VK_COMPONENT_SWIZZLE_R };
		view.subresourceRange = { VK_IMAGE_ASPECT_COLOR_BIT, 0, 1, 0, 1 };
		view.subresourceRange.layerCount = 6;
		view.image = shadowCubeMap.image;
		VK_CHECK_RESULT(vkCreateImageView(device, &view, nullptr, &shadowCubeMap.view));

		view.viewType = VK_IMAGE_VIEW_TYPE_2D;
		view.subresourceRange.layerCount = 1;
		view.image = shadowCubeMap.image;

		for (uint32_t i = 0; i < 6; i++)
		{
			view.subresourceRange.baseArrayLayer = i;
			VK_CHECK_RESULT(vkCreateImageView(device, &view, nullptr, &shadowCubeMapFaceImageViews[i]));
		}
	}

	// Set up a separate render pass for the offscreen frame buffer
	// This is necessary as the offscreen frame buffer attachments
	// use formats different to the ones from the visible frame buffer
	// and at least the depth one may not be compatible
	void prepareOffscreenRenderpass()
	{
		VkAttachmentDescription osAttachments[2] = {};

		// Find a suitable depth format for
		VkBool32 validDepthFormat = vks::tools::getSupportedDepthFormat(physicalDevice, &offscreenDepthFormat);
		assert(validDepthFormat);

		osAttachments[0].format = offscreenImageFormat;
		osAttachments[0].samples = VK_SAMPLE_COUNT_1_BIT;
		osAttachments[0].loadOp = VK_ATTACHMENT_LOAD_OP_CLEAR;
		osAttachments[0].storeOp = VK_ATTACHMENT_STORE_OP_STORE;
		osAttachments[0].stencilLoadOp = VK_ATTACHMENT_LOAD_OP_DONT_CARE;
		osAttachments[0].stencilStoreOp = VK_ATTACHMENT_STORE_OP_DONT_CARE;
		osAttachments[0].initialLayout = VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL;
		osAttachments[0].finalLayout = VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL;

		// Depth attachment
		osAttachments[1].format = offscreenDepthFormat;
		osAttachments[1].samples = VK_SAMPLE_COUNT_1_BIT;
		osAttachments[1].loadOp = VK_ATTACHMENT_LOAD_OP_CLEAR;
		osAttachments[1].storeOp = VK_ATTACHMENT_STORE_OP_STORE;
		osAttachments[1].stencilLoadOp = VK_ATTACHMENT_LOAD_OP_DONT_CARE;
		osAttachments[1].stencilStoreOp = VK_ATTACHMENT_STORE_OP_DONT_CARE;
		osAttachments[1].initialLayout = VK_IMAGE_LAYOUT_DEPTH_STENCIL_ATTACHMENT_OPTIMAL;
		osAttachments[1].finalLayout = VK_IMAGE_LAYOUT_DEPTH_STENCIL_ATTACHMENT_OPTIMAL;

		VkAttachmentReference colorReference = {};
		colorReference.attachment = 0;
		colorReference.layout = VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL;

		VkAttachmentReference depthReference = {};
		depthReference.attachment = 1;
		depthReference.layout = VK_IMAGE_LAYOUT_DEPTH_STENCIL_ATTACHMENT_OPTIMAL;

		VkSubpassDescription subpass = {};
		subpass.pipelineBindPoint = VK_PIPELINE_BIND_POINT_GRAPHICS;
		subpass.colorAttachmentCount = 1;
		subpass.pColorAttachments = &colorReference;
		subpass.pDepthStencilAttachment = &depthReference;

		VkRenderPassCreateInfo renderPassCreateInfo = vks::initializers::renderPassCreateInfo();
		renderPassCreateInfo.attachmentCount = 2;
		renderPassCreateInfo.pAttachments = osAttachments;
		renderPassCreateInfo.subpassCount = 1;
		renderPassCreateInfo.pSubpasses = &subpass;

		VK_CHECK_RESULT(vkCreateRenderPass(device, &renderPassCreateInfo, nullptr, &offscreenPass.renderPass));
	}

	// Prepare a new framebuffer for offscreen rendering
	// The contents of this framebuffer are then
	// copied to the different cube map faces
	void prepareOffscreenFramebuffer()
	{
		offscreenPass.width = offscreenImageSize;
		offscreenPass.height = offscreenImageSize;

		// Color attachment
		VkImageCreateInfo imageCreateInfo = vks::initializers::imageCreateInfo();
		imageCreateInfo.imageType = VK_IMAGE_TYPE_2D;
		imageCreateInfo.format = offscreenImageFormat;
		imageCreateInfo.extent.width = offscreenPass.width;
		imageCreateInfo.extent.height = offscreenPass.height;
		imageCreateInfo.extent.depth = 1;
		imageCreateInfo.mipLevels = 1;
		imageCreateInfo.arrayLayers = 1;
		imageCreateInfo.samples = VK_SAMPLE_COUNT_1_BIT;
		imageCreateInfo.tiling = VK_IMAGE_TILING_OPTIMAL;
		// Image of the framebuffer is blit source
		imageCreateInfo.initialLayout = VK_IMAGE_LAYOUT_UNDEFINED;
		imageCreateInfo.usage = VK_IMAGE_USAGE_COLOR_ATTACHMENT_BIT | VK_IMAGE_USAGE_TRANSFER_SRC_BIT;
		imageCreateInfo.sharingMode = VK_SHARING_MODE_EXCLUSIVE;

		VkImageViewCreateInfo colorImageView = vks::initializers::imageViewCreateInfo();
		colorImageView.viewType = VK_IMAGE_VIEW_TYPE_2D;
		colorImageView.format = offscreenImageFormat;
		colorImageView.flags = 0;
		colorImageView.subresourceRange = {};
		colorImageView.subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
		colorImageView.subresourceRange.baseMipLevel = 0;
		colorImageView.subresourceRange.levelCount = 1;
		colorImageView.subresourceRange.baseArrayLayer = 0;
		colorImageView.subresourceRange.layerCount = 1;

		VkCommandBuffer layoutCmd = vulkanDevice->createCommandBuffer(VK_COMMAND_BUFFER_LEVEL_PRIMARY, true);

		// Depth stencil attachment
		imageCreateInfo.format = offscreenDepthFormat;
		imageCreateInfo.usage = VK_IMAGE_USAGE_DEPTH_STENCIL_ATTACHMENT_BIT | VK_IMAGE_USAGE_TRANSFER_SRC_BIT;

		VkImageViewCreateInfo depthStencilView = vks::initializers::imageViewCreateInfo();
		depthStencilView.viewType = VK_IMAGE_VIEW_TYPE_2D;
		depthStencilView.format = offscreenDepthFormat;
		depthStencilView.flags = 0;
		depthStencilView.subresourceRange = {};
		depthStencilView.subresourceRange.aspectMask = VK_IMAGE_ASPECT_DEPTH_BIT;
		if (offscreenDepthFormat >= VK_FORMAT_D16_UNORM_S8_UINT) {
			depthStencilView.subresourceRange.aspectMask |= VK_IMAGE_ASPECT_STENCIL_BIT;
		}
		depthStencilView.subresourceRange.baseMipLevel = 0;
		depthStencilView.subresourceRange.levelCount = 1;
		depthStencilView.subresourceRange.baseArrayLayer = 0;
		depthStencilView.subresourceRange.layerCount = 1;

		VK_CHECK_RESULT(vkCreateImage(device, &imageCreateInfo, nullptr, &offscreenPass.depth.image));

		VkMemoryRequirements memReqs;
		vkGetImageMemoryRequirements(device, offscreenPass.depth.image, &memReqs);
		
		VkMemoryAllocateInfo memAlloc = vks::initializers::memoryAllocateInfo();
		memAlloc.allocationSize = memReqs.size;
		memAlloc.memoryTypeIndex = vulkanDevice->getMemoryType(memReqs.memoryTypeBits, VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT);
		VK_CHECK_RESULT(vkAllocateMemory(device, &memAlloc, nullptr, &offscreenPass.depth.mem));
		VK_CHECK_RESULT(vkBindImageMemory(device, offscreenPass.depth.image, offscreenPass.depth.mem, 0));

		vks::tools::setImageLayout(
			layoutCmd,
			offscreenPass.depth.image,
			VK_IMAGE_ASPECT_DEPTH_BIT | VK_IMAGE_ASPECT_STENCIL_BIT,
			VK_IMAGE_LAYOUT_UNDEFINED,
			VK_IMAGE_LAYOUT_DEPTH_STENCIL_ATTACHMENT_OPTIMAL);

		vulkanDevice->flushCommandBuffer(layoutCmd, queue, true);

		depthStencilView.image = offscreenPass.depth.image;
		VK_CHECK_RESULT(vkCreateImageView(device, &depthStencilView, nullptr, &offscreenPass.depth.view));

		VkImageView attachments[2];
		attachments[1] = offscreenPass.depth.view;

		VkFramebufferCreateInfo fbufCreateInfo = vks::initializers::framebufferCreateInfo();
		fbufCreateInfo.renderPass = offscreenPass.renderPass;
		fbufCreateInfo.attachmentCount = 2;
		fbufCreateInfo.pAttachments = attachments;
		fbufCreateInfo.width = offscreenPass.width;
		fbufCreateInfo.height = offscreenPass.height;
		fbufCreateInfo.layers = 1;

		for (uint32_t i = 0; i < 6; i++)
		{
			attachments[0] = shadowCubeMapFaceImageViews[i];
			VK_CHECK_RESULT(vkCreateFramebuffer(device, &fbufCreateInfo, nullptr, &offscreenPass.frameBuffers[i]));
		}
	}

	void loadAssets()
	{
		const uint32_t glTFLoadingFlags = vkglTF::FileLoadingFlags::PreTransformVertices | vkglTF::FileLoadingFlags::PreMultiplyVertexColors | vkglTF::FileLoadingFlags::FlipY;
		models.debugcube.loadFromFile(getAssetPath() + "models/cube.gltf", vulkanDevice, queue, glTFLoadingFlags);
		models.scene.loadFromFile(getAssetPath() + "models/shadowscene_fire.gltf", vulkanDevice, queue, glTFLoadingFlags);
	}

	void setupDescriptors()
	{
		// Pool
		std::vector<VkDescriptorPoolSize> poolSizes = {
			vks::initializers::descriptorPoolSize(VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER, maxConcurrentFrames * 3),
			vks::initializers::descriptorPoolSize(VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, maxConcurrentFrames *  2)
		};
		VkDescriptorPoolCreateInfo descriptorPoolInfo = vks::initializers::descriptorPoolCreateInfo(poolSizes, maxConcurrentFrames * 2);
		VK_CHECK_RESULT(vkCreateDescriptorPool(device, &descriptorPoolInfo, nullptr, &descriptorPool));

		// Layout
		std::vector<VkDescriptorSetLayoutBinding> setLayoutBindings = {
			// Binding 0 : Vertex shader uniform buffer
			vks::initializers::descriptorSetLayoutBinding(VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER, VK_SHADER_STAGE_VERTEX_BIT, 0),
			// Binding 1 : Fragment shader image sampler (cube map)
			vks::initializers::descriptorSetLayoutBinding(VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, VK_SHADER_STAGE_FRAGMENT_BIT, 1)
		};
		VkDescriptorSetLayoutCreateInfo descriptorLayout = vks::initializers::descriptorSetLayoutCreateInfo(setLayoutBindings);
		VK_CHECK_RESULT(vkCreateDescriptorSetLayout(device, &descriptorLayout, nullptr, &descriptorSetLayout));

		// Sets per frame, just like the buffers themselves
		// Images do not need to be duplicated per frame, we reuse the same one for each frame
		VkDescriptorImageInfo texDescriptor = vks::initializers::descriptorImageInfo(shadowCubeMap.sampler, shadowCubeMap.view, VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL);
		VkDescriptorSetAllocateInfo allocInfo = vks::initializers::descriptorSetAllocateInfo(descriptorPool, &descriptorSetLayout, 1);
		for (auto i = 0; i < uniformBuffers.size(); i++) {
			// Scene display
			VK_CHECK_RESULT(vkAllocateDescriptorSets(device, &allocInfo, &descriptorSets[i].scene));

			std::vector<VkWriteDescriptorSet> sceneDescriptorSets = {
				// Binding 0 : Vertex shader uniform buffer
				vks::initializers::writeDescriptorSet(descriptorSets[i].scene, VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER, 0, &uniformBuffers[i].scene.descriptor),
				// Binding 1 : Fragment shader shadow sampler
				vks::initializers::writeDescriptorSet(descriptorSets[i].scene, VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, 1, &texDescriptor)
			};
			vkUpdateDescriptorSets(device, static_cast<uint32_t>(sceneDescriptorSets.size()), sceneDescriptorSets.data(), 0, nullptr);

			// Offscreen
			VK_CHECK_RESULT(vkAllocateDescriptorSets(device, &allocInfo, &descriptorSets[i].offscreen));
			std::vector<VkWriteDescriptorSet> offScreenWriteDescriptorSets = {
				// Binding 0 : Vertex shader uniform buffer
				vks::initializers::writeDescriptorSet(descriptorSets[i].offscreen, VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER, 0, &uniformBuffers[i].offscreen.descriptor),
			};
			vkUpdateDescriptorSets(device, static_cast<uint32_t>(offScreenWriteDescriptorSets.size()), offScreenWriteDescriptorSets.data(), 0, nullptr);
		}
	}

	void preparePipelines()
	{
		// Layouts
		// 3D scene pipeline layout
		VkPipelineLayoutCreateInfo pipelineLayoutCreateInfo = vks::initializers::pipelineLayoutCreateInfo(&descriptorSetLayout, 1);
		VK_CHECK_RESULT(vkCreatePipelineLayout(device, &pipelineLayoutCreateInfo, nullptr, &pipelineLayouts.scene));

		// Offscreen pipeline layout
		// Push constants for cube map face view matrices
		VkPushConstantRange pushConstantRange = vks::initializers::pushConstantRange(VK_SHADER_STAGE_VERTEX_BIT, sizeof(glm::mat4), 0);
		// Push constant ranges are part of the pipeline layout
		pipelineLayoutCreateInfo.pushConstantRangeCount = 1;
		pipelineLayoutCreateInfo.pPushConstantRanges = &pushConstantRange;
		VK_CHECK_RESULT(vkCreatePipelineLayout(device, &pipelineLayoutCreateInfo, nullptr, &pipelineLayouts.offscreen));


		// Pipelines
		VkPipelineInputAssemblyStateCreateInfo inputAssemblyState = vks::initializers::pipelineInputAssemblyStateCreateInfo(VK_PRIMITIVE_TOPOLOGY_TRIANGLE_LIST, 0, VK_FALSE);
		VkPipelineRasterizationStateCreateInfo rasterizationState = vks::initializers::pipelineRasterizationStateCreateInfo(VK_POLYGON_MODE_FILL, VK_CULL_MODE_BACK_BIT, VK_FRONT_FACE_COUNTER_CLOCKWISE, 0);
		VkPipelineColorBlendAttachmentState blendAttachmentState = vks::initializers::pipelineColorBlendAttachmentState(0xf, VK_FALSE);
		VkPipelineColorBlendStateCreateInfo colorBlendState = vks::initializers::pipelineColorBlendStateCreateInfo(1, &blendAttachmentState);
		VkPipelineDepthStencilStateCreateInfo depthStencilState = vks::initializers::pipelineDepthStencilStateCreateInfo(VK_TRUE, VK_TRUE, VK_COMPARE_OP_LESS_OR_EQUAL);
		VkPipelineViewportStateCreateInfo viewportState = vks::initializers::pipelineViewportStateCreateInfo(1, 1, 0);
		VkPipelineMultisampleStateCreateInfo multisampleState = vks::initializers::pipelineMultisampleStateCreateInfo(VK_SAMPLE_COUNT_1_BIT, 0);
		std::vector<VkDynamicState> dynamicStateEnables = { VK_DYNAMIC_STATE_VIEWPORT, VK_DYNAMIC_STATE_SCISSOR };
		VkPipelineDynamicStateCreateInfo dynamicState = vks::initializers::pipelineDynamicStateCreateInfo(dynamicStateEnables);

		// 3D scene pipeline
		// Load shaders
		std::array<VkPipelineShaderStageCreateInfo, 2> shaderStages;

		shaderStages[0] = loadShader(getShadersPath() + "shadowmappingomni/scene.vert.spv", VK_SHADER_STAGE_VERTEX_BIT);
		shaderStages[1] = loadShader(getShadersPath() + "shadowmappingomni/scene.frag.spv", VK_SHADER_STAGE_FRAGMENT_BIT);

		VkGraphicsPipelineCreateInfo pipelineCI = vks::initializers::pipelineCreateInfo(pipelineLayouts.scene, renderPass, 0);
		pipelineCI.pInputAssemblyState = &inputAssemblyState;
		pipelineCI.pRasterizationState = &rasterizationState;
		pipelineCI.pColorBlendState = &colorBlendState;
		pipelineCI.pMultisampleState = &multisampleState;
		pipelineCI.pViewportState = &viewportState;
		pipelineCI.pDepthStencilState = &depthStencilState;
		pipelineCI.pDynamicState = &dynamicState;
		pipelineCI.stageCount = static_cast<uint32_t>(shaderStages.size());
		pipelineCI.pStages = shaderStages.data();
		pipelineCI.pVertexInputState = vkglTF::Vertex::getPipelineVertexInputState({vkglTF::VertexComponent::Position, vkglTF::VertexComponent::Color, vkglTF::VertexComponent::Normal});
		VK_CHECK_RESULT(vkCreateGraphicsPipelines(device, pipelineCache, 1, &pipelineCI, nullptr, &pipelines.scene));

		// Offscreen pipeline
		shaderStages[0] = loadShader(getShadersPath() + "shadowmappingomni/offscreen.vert.spv", VK_SHADER_STAGE_VERTEX_BIT);
		shaderStages[1] = loadShader(getShadersPath() + "shadowmappingomni/offscreen.frag.spv", VK_SHADER_STAGE_FRAGMENT_BIT);
		pipelineCI.layout = pipelineLayouts.offscreen;
		pipelineCI.renderPass = offscreenPass.renderPass;
		VK_CHECK_RESULT(vkCreateGraphicsPipelines(device, pipelineCache, 1, &pipelineCI, nullptr, &pipelines.offscreen));

		// Cube map display pipeline
		shaderStages[0] = loadShader(getShadersPath() + "shadowmappingomni/cubemapdisplay.vert.spv", VK_SHADER_STAGE_VERTEX_BIT);
		shaderStages[1] = loadShader(getShadersPath() + "shadowmappingomni/cubemapdisplay.frag.spv", VK_SHADER_STAGE_FRAGMENT_BIT);
		VkPipelineVertexInputStateCreateInfo emptyInputState = vks::initializers::pipelineVertexInputStateCreateInfo();
		pipelineCI.pVertexInputState = &emptyInputState;
		pipelineCI.layout = pipelineLayouts.scene;
		pipelineCI.renderPass = renderPass;
		rasterizationState.cullMode = VK_CULL_MODE_NONE;
		VK_CHECK_RESULT(vkCreateGraphicsPipelines(device, pipelineCache, 1, &pipelineCI, nullptr, &pipelines.cubemapDisplay));
	}

	// Prepare and initialize uniform buffer containing shader uniforms
	void prepareUniformBuffers()
	{
		for (auto& buffer : uniformBuffers) {
			// Offscreen uniform buffer
			VK_CHECK_RESULT(vulkanDevice->createBuffer(VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT, VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT, &buffer.offscreen, sizeof(UniformData)));
			// Scene uniform buffer
			VK_CHECK_RESULT(vulkanDevice->createBuffer(VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT, VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT, &buffer.scene, sizeof(UniformData)));
			// Map persistent
			VK_CHECK_RESULT(buffer.offscreen.map());
			VK_CHECK_RESULT(buffer.scene.map());
		}
	}

	void updateUniformBuffers()
	{
		// Depth rendering
		if (!paused) {
			lightPos.x = sin(glm::radians(timer * 360.0f)) * 0.15f;
			lightPos.z = cos(glm::radians(timer * 360.0f)) * 0.15f;
		}
		uniformDataOffscreen.projection = glm::perspective((float)(M_PI / 2.0), 1.0f, zNear, zFar);
		uniformDataOffscreen.view = glm::mat4(1.0f);
		uniformDataOffscreen.model = glm::translate(glm::mat4(1.0f), glm::vec3(-lightPos.x, -lightPos.y, -lightPos.z));
		uniformDataOffscreen.lightPos = lightPos;
		memcpy(uniformBuffers[currentBuffer].offscreen.mapped, &uniformDataOffscreen, sizeof(UniformData));

		// Scene rendering
		uniformDataScene.projection = camera.matrices.perspective;
		uniformDataScene.view = camera.matrices.view;
		uniformDataScene.model = glm::mat4(1.0f);
		uniformDataScene.lightPos = lightPos;
		memcpy(uniformBuffers[currentBuffer].scene.mapped, &uniformDataScene, sizeof(UniformData));
	}

	void prepare()
	{
		VulkanExampleBase::prepare();
		loadAssets();
		prepareUniformBuffers();
		prepareCubeMap();
		setupDescriptors();
		prepareOffscreenRenderpass();
		preparePipelines();
		prepareOffscreenFramebuffer();
		prepared = true;
	}

	// Updates a single cube map face
	// Renders the scene with face's view directly to the cubemap layer `faceIndex`
	// Uses push constants for quick update of view matrix for the current cube map face
	void updateCubeFace(uint32_t faceIndex, VkCommandBuffer commandBuffer)
	{
		VkClearValue clearValues[2];
		clearValues[0].color = { { 0.0f, 0.0f, 0.0f, 1.0f } };
		clearValues[1].depthStencil = { 1.0f, 0 };

		VkRenderPassBeginInfo renderPassBeginInfo = vks::initializers::renderPassBeginInfo();
		// Reuse render pass from example pass
		renderPassBeginInfo.renderPass = offscreenPass.renderPass;
		renderPassBeginInfo.framebuffer = offscreenPass.frameBuffers[faceIndex];
		renderPassBeginInfo.renderArea.extent.width = offscreenPass.width;
		renderPassBeginInfo.renderArea.extent.height = offscreenPass.height;
		renderPassBeginInfo.clearValueCount = 2;
		renderPassBeginInfo.pClearValues = clearValues;

		// Update view matrix via push constant

		glm::mat4 viewMatrix = glm::mat4(1.0f);
		switch (faceIndex)
		{
		case 0: // POSITIVE_X
			viewMatrix = glm::rotate(viewMatrix, glm::radians(90.0f), glm::vec3(0.0f, 1.0f, 0.0f));
			viewMatrix = glm::rotate(viewMatrix, glm::radians(180.0f), glm::vec3(1.0f, 0.0f, 0.0f));
			break;
		case 1:	// NEGATIVE_X
			viewMatrix = glm::rotate(viewMatrix, glm::radians(-90.0f), glm::vec3(0.0f, 1.0f, 0.0f));
			viewMatrix = glm::rotate(viewMatrix, glm::radians(180.0f), glm::vec3(1.0f, 0.0f, 0.0f));
			break;
		case 2:	// POSITIVE_Y
			viewMatrix = glm::rotate(viewMatrix, glm::radians(-90.0f), glm::vec3(1.0f, 0.0f, 0.0f));
			break;
		case 3:	// NEGATIVE_Y
			viewMatrix = glm::rotate(viewMatrix, glm::radians(90.0f), glm::vec3(1.0f, 0.0f, 0.0f));
			break;
		case 4:	// POSITIVE_Z
			viewMatrix = glm::rotate(viewMatrix, glm::radians(180.0f), glm::vec3(1.0f, 0.0f, 0.0f));
			break;
		case 5:	// NEGATIVE_Z
			viewMatrix = glm::rotate(viewMatrix, glm::radians(180.0f), glm::vec3(0.0f, 0.0f, 1.0f));
			break;
		}

		// Render scene from cube face's point of view
		vkCmdBeginRenderPass(commandBuffer, &renderPassBeginInfo, VK_SUBPASS_CONTENTS_INLINE);

		// Update shader push constant block
		// Contains current face view matrix
		vkCmdPushConstants(
			commandBuffer,
			pipelineLayouts.offscreen,
			VK_SHADER_STAGE_VERTEX_BIT,
			0,
			sizeof(glm::mat4),
			&viewMatrix);

		vkCmdBindPipeline(commandBuffer, VK_PIPELINE_BIND_POINT_GRAPHICS, pipelines.offscreen);
		vkCmdBindDescriptorSets(commandBuffer, VK_PIPELINE_BIND_POINT_GRAPHICS, pipelineLayouts.offscreen, 0, 1, &descriptorSets[currentBuffer].offscreen, 0, nullptr);
		models.scene.draw(commandBuffer);

		vkCmdEndRenderPass(commandBuffer);
	}

	void buildCommandBuffer()
	{
		VkCommandBuffer cmdBuffer = drawCmdBuffers[currentBuffer];
		
		VkCommandBufferBeginInfo cmdBufInfo = vks::initializers::commandBufferBeginInfo();

		VK_CHECK_RESULT(vkBeginCommandBuffer(cmdBuffer, &cmdBufInfo));

		/*
			Generate shadow cube maps using one render pass per face
		*/
		{
			VkViewport viewport = vks::initializers::viewport((float)offscreenPass.width, (float)offscreenPass.height, 0.0f, 1.0f);
			vkCmdSetViewport(cmdBuffer, 0, 1, &viewport);

			VkRect2D scissor = vks::initializers::rect2D(offscreenPass.width, offscreenPass.height, 0, 0);
			vkCmdSetScissor(cmdBuffer, 0, 1, &scissor);

			for (uint32_t face = 0; face < 6; face++) {
				updateCubeFace(face, cmdBuffer);
			}
		}

		/*
			Note: Explicit synchronization is not required between the render pass, as this is done implicit via sub pass dependencies
		*/

		/*
			Scene rendering with applied shadow map
		*/
		{
			VkClearValue clearValues[2];
			clearValues[0].color = defaultClearColor;
			clearValues[1].depthStencil = { 1.0f, 0 };

			VkRenderPassBeginInfo renderPassBeginInfo = vks::initializers::renderPassBeginInfo();
			renderPassBeginInfo.renderPass = renderPass;
			renderPassBeginInfo.framebuffer = frameBuffers[currentImageIndex];
			renderPassBeginInfo.renderArea.extent.width = width;
			renderPassBeginInfo.renderArea.extent.height = height;
			renderPassBeginInfo.clearValueCount = 2;
			renderPassBeginInfo.pClearValues = clearValues;

			vkCmdBeginRenderPass(cmdBuffer, &renderPassBeginInfo, VK_SUBPASS_CONTENTS_INLINE);

			VkViewport viewport = vks::initializers::viewport((float)width, (float)height, 0.0f, 1.0f);
			vkCmdSetViewport(cmdBuffer, 0, 1, &viewport);

			VkRect2D scissor = vks::initializers::rect2D(width, height, 0, 0);
			vkCmdSetScissor(cmdBuffer, 0, 1, &scissor);

			vkCmdBindDescriptorSets(cmdBuffer, VK_PIPELINE_BIND_POINT_GRAPHICS, pipelineLayouts.scene, 0, 1, &descriptorSets[currentBuffer].scene, 0, nullptr);

			if (displayCubeMap)
			{
				// Display all six sides of the shadow cube map
				// Note: Visualization of the different faces is done in the fragment shader, see cubemapdisplay.frag
				vkCmdBindPipeline(cmdBuffer, VK_PIPELINE_BIND_POINT_GRAPHICS, pipelines.cubemapDisplay);
				models.debugcube.draw(cmdBuffer);
			}
			else
			{
				vkCmdBindPipeline(cmdBuffer, VK_PIPELINE_BIND_POINT_GRAPHICS, pipelines.scene);
				models.scene.draw(cmdBuffer);
			}

			drawUI(cmdBuffer);

			vkCmdEndRenderPass(cmdBuffer);
		}

		VK_CHECK_RESULT(vkEndCommandBuffer(cmdBuffer));
	}

	virtual void render()
	{
		if (!prepared)
			return;
		VulkanExampleBase::prepareFrame();
		updateUniformBuffers();
		buildCommandBuffer();
		VulkanExampleBase::submitFrame();
	}

	virtual void OnUpdateUIOverlay(vks::UIOverlay *overlay)
	{
		if (overlay->header("Settings")) {
			overlay->checkBox("Display shadow cube render target", &displayCubeMap);
		}
	}
};

VULKAN_EXAMPLE_MAIN()
